This proposal describes the CENTRAL BIOCHEMISTRY LABORATORY (CBL) for the Hypertension Genetic Epidemiology Network (HyperGEN) application submitted in response to a request for applications for networks to examine Genetic Determinants of High Blood Pressure(RFA #HL-94-01 l). It describes the CBL research team and research plan from the University of Minnesota's Department of Laboratory Medicine and Pathology for providing analytical support for phenotypic analysis of HyperGEN participants who will be selected as describe in the HyperGEN MASTER RESEARCH PLAN. We estimate approximately 4,000 participants and 600 relatives not on antihypertensive medications, half of whom will be Blacks, will be examined. The role of HyperGEN's CBL is to measure a variety of "routine" analytes in all 4,600 HyperGEN participants and relatives and a variety of "special" tests in the 600 relatives plus 400 random controls using urine (U), serum (S), and plasma (P). The anticipated 4,600 "routine" tests include: U & S sodium, U & S potassium, U & S magnesium, U & S calcium, U & S creatinine, S phosphorus, S uric acid, S albumin, S glucose, S insulin, S total cholesterol, S triglyceride, S HDL-cholesterol, and S calculated and measured LDL-cholesterol. The anticipated 1,000 "special" tests include: U kallikrein, U 6-OH-cortisol, U aldosterone, U prostaglandin E2, U thromboxane B2, U catecholamines, P renin activity, P angiotensinogen, P endothelin, and P atrial natriuretic peptide. We also propose to measure red cell sodium countertransport and sodium-potassium cotransport in the 600 non-medicated relatives and 400 random controls. Finally, we propose to collect, isolate, purify, and store DNA from all 4,600 of the HyperGEN participants and non-medicated relatives so the genetic analyses as described in the HyperGEN MASTER RESEARCH PLAN can be performed.